Engine starting apparatus



2 Sheets-Sheet l May 10, 1938. H. A. THORNBURG ET AL ENGINE STARTING`.QPPARTUSl Filed July e, 1936 May 1938- v H. A. THORNBURG ET AL2,117,230

ENGINE STARTING APPARATUS Filed July 8, 1956 2 Sheets-Sheet 2 PatentedMay 10, 1938 UNITED STATES PATENT OFFICE ENGINE STARTING APPARATUS awareApplication July 8, 1936, Serial No. 89,503

5 Claims.

This invention relates to apparatus for starting an internal combustionengine and particularly to the type of apparatus which comprises anelectric motor and a pinion driven by motor and movable axially intomesh with the fly-wheel or other gear of the engine to be started. Inthis type of apparatus the pinion is withdrawn from the flywheel gearafter the engine has been started.

It is one of the objects of the present invention to prevent engagingthe motor-driven pinion with the engine gear in case the engine isrunning prior to moving the pinion into engagement therewith.

In the disclosed embodiment of this invention the present object isaccomplished by providing a part adapted to make substantially noiselesscontact with an end face of an engine flywheel and to be moved inresponse to contact with the moving ywheel into such position as topositively stop movement of the motor pinion into engagement with theflywheel gear.

The present invention is adapted for any sort of motor vehicle propelledby an internal combustion engine and is particularly useful on passengerbusses of the type where the engine is located on the side or at therear of the vehicle and so far from the drivers seat that the operationof the engine when idling is not audibly perceptible. It occasionallyhappens that the operator, believing that the engine has stopped,whereas in fact it is idling, will operate the starter control buttoncausing the starter pinion to mesh with the flywheel gear. Theengagement of the starter pinion with the flywheel gear while the engineis running produces a disagreeable noise and is damaging to the gearteeth. Such noise or darnage is avoided by the use of the presentinvention.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawings wherein a preferred embodiment of the present invention isclearly shown.

In the drawings:

Figure 1 is in part a longitudinal sectional View of the startingapparatus embodying the present invention and in part a wirin-g diagram;

Figures 2 and 3 are sectional Views taken respectively on the lines 2--2and 3-3 of Figure 1;

Figures 4, 5, and 6 are fragmentary side views partly in section of theengine starter drive, showing the same in various positions; and

Figure 7 is in part an end View of the pinion and clutch assembly and inpart a sectional view of the clutch, the end view being taken in the ,Adirection of the arrow A1ct of Figure 6, the sectional View being takenon the line 1 1 of Figure 6.

Referring now to Figure 1, numeral 29 designates the electric motorcomprising afield winding 2 I an armature 22 and brushes 23 and 24, thelatter of which is grounded at 25. This motor drives the shaft 26 whichis supported by bearings carried by the frame of the motor. The left endframe is not shown, but it will be understood to be attached to theleft-hand end of the field frame 21 which carries the field winding 2|.The right end frame or gear housing of the motor is designated bynumeral 28, and it carries a bearing 29 for the right-hand end of theshaft 26.

The shaft 26 is provided with longitudinal splines 3U which cooperatewith longitudinal splines 3l provided in the sleeve 32 of the innermember or clutch cam 33 of an overrunning clutch.` This clutch comprisesalso a driven member or shell 34 and a series of rollers 35 eachl ofwhich is located between the inner cylindrical surfaces of shell 34 anda cam surface 33a which is not concentric with the shell. The surfaces33d are so arranged with respect to the shell 34 that, as the clutchinner member 33 rotates clockwise as viewed by the arrow 36 in Figure'7, clockwise rotation will be imparted to the shell 34. Obviously theshell 34 may overrun in a clockwise direction with respect to the innerdriving member 33 when one Views it as shown in Figure '7. The clutchinner member 33 carries a bearing bushing 31 which is journaled on thereduced end portion 26a. of the shaft 26. The portion 26a, supportsabearing bushing 38 press-fitted into the hub of a starting motor pinion39 which is adapted to move axially along the shaft portion 26a intomesh with the iiywheel gear 40 of the engine to be started. The pinion39 is drivingly connected with the shell 34 by providing the latter withan annular boss 4| into which are provided a series of depressions, eachadapted to receive an end portion of a tooth of the pinion 39 when thepinion is fixed to the shell 34, as shown in Figure 1. To secure thepinion 39 to the shell 34 the pinion is provided with an annular flange42 which is passed through a central orifice in the shell 34 and isriveted over against the shell 34, as indicated at 43.

This overrunning clutch and pinion assembly is moved along the shaft 26by means of a pinion meshing means including shifter sleeve 50 providedwith an annular groove 5| for receiving pins or studs 52 located ondiametrically opposite sides of the sleeve 50 and carried by spaced arms53 of al lever 54 pivoted upon a rod 55 carried by the frame 28. The rod55 is surrounded by a coil spring 56, one end 51 of which bearsdownwardly against the frame 28, as indicated by the arrow 51a and theother end 58 of which bears in the direction of the arrow 59 against apin 58 carried by the lever 54. Counterclockwise rotation of the lever54 causes the sleeve 58 to move toward the right, as shown in Figure 1.The sleeve 58 has a central bore 6| which has a sliding t with the shaft26 and has a part 62 provided with a central bore E3 having a slidingiit with respect to the sleeve 32. Between the right-hand end of part 52and the left-hand end of a washer 64 surrounding the sleeve 32 andbearing against the clutch cam 33, there is located a coil spring 65which normally is somewhat compressed. Spring 65, therefore, forces thepart 62 a denite distance away from the washer 64 and clutch cam 33. Theseparation of the parts 62 from the parts 64 is limited by a wire splitring 66 which is snapped into a groove provided by the sleeve 32 andwhich bears against a beveled surface 81 provided on the left-hand endof the part 62. The part 62 is joined with the main part of the sleeve58 by an arcuate web 68 shown best in Figure 2. This web 68 is spacedfrom the shaft 26 suiiiciently to permit assembling the split ring 66.Quite obviously, motion of the sleeve toward the right as eiected bycounterclockwise rotation of the lever 54 will cause the motion to beimparted through the spring 65 to the clutch and pinion assembly therebycausing the pinion 39 to move into engagement with the engine gear 48.

The lever 54 is moved in a counterclockwise direction by direct manualoperation or by the electromagnetic means shown diagrammatically inFigure 1. 'I'his electromagnetic means comprises an electromagnet havingtwo windings 18 of relatively fine wire and 1| of relatively coarsewire. These windings surround a non-magnetic tube 12 which provides aguide for the movement of a magnetizable armature 13 toward a stationarymagnetizable core member 14 also located within the magnetic field whichis created by current passing through these windings. The core 14 isattached to the magnetizable discs 15 which are in contact with amagnetizable shell 16 and in contact also with m'agnetizable discs 11and 18 which are h'eld by the sleeve 12 concentric with respect to thearmature 13.

The starting motor 28 is energized by current from a storage battery 88which is grounded at 8| and which is connected by wire 82 with a starterswitch contact 83. Contact 83 is connected by a movable Contact 84 witha stationary contact 85 which is connected with winding 1| and with theseries field 2| of the starting motor. The contact 84 is insulatinglysupported by a tubular metallic rivet 88 which is slidable upon a rod 81which extends through the core 14 and is guided thereby. The rod 81carries a washer 88 against which the tubular rivet 86 is urged byspring 89 located between a washer 98 xed to the rod 81 and a washer 9|loosely mounted on the rod 86. The washer 98 is held against the leftend face of core 14 by a spring 92 which surrounds a stud 93 carried bya fixed part 94 and projects into an axial. bore 94 in the pin 81. Thespring 92, therefore, serves to maintain the contact 84 out ofengagement with contacts 83 and 85, and the righthand end of plunger 81in such position as to be normally engaged by the left-hand end of core13. The winding 18 is grounded at 18.

The armature 13 is centrally tapped to receive the threaded shank |88 ofa stud |8| which is connected by cross pin |82 with a .link |03 havingan elongated slot |84 through which passes a pin |85 connecting the link|83 with the lever 54. The two windings 18 and 1| are connected with thebattery by push-button switch |8.

To start the engine, the operator closes the switch ||8 thereby causingthe current to flow from the battery through the switch and through thewindings 10 and 1| and back to the ground connection 18a. Current willalso flow from the battery through the switch I8, winding 1|, startingmotor 20, and back to the battery through the ground connections 25 and8|. The electromagnet will be energized suiciently to cause the armature13 to move toward the left in order to cause that counterclockwiserotation of the lever 54 and that axial movement of sleeve 58 which willmove the motor pinion 39 into mesh with the engine gear 48. During thismovement of the armature 13, it will engage the rod 81 to cause it tomove toward the left and the contact 84 to be engaged with the contacts83 and 85 under yielding pressure afforded by the spring 89. When thisoccurs the motor will receive current from the battery and the shaft 26will rotate and the pinion 39 will drive the engine gear 48 in suchdirection as to cause the engine to be started. After the engine hasbeen started the operator releases the push-button switch I8 therebycausing the electromagnet to be deenergized, whereupon the lever 54 ismoved clockwise into its original position due tol the action of thespring 56, and the pinion 39l is withdrawn from the engine gear 48. Thearmature 13 having been withdrawn from the rod 81, the spring 92 movesthe rod 81 back to its normal position thereby disengaging the contact84 from the contacts 83 and 85, whereupon the motor 28 is disconnectedfrom the battery 88 and the motor stops.

When the contact 84 engages the contacts 83 and the winding 1| of coarsewire will be short circuited so that a greater amount of current willflow from the battery to the starting motor than before. At the timecontact 84 engages with contacts 83 and 85 to short circuit the winding1| the air gap between the core 14 and armature 13 is relatively smalland, therefore, the magnetic force produced by the coil 18 alone issufficient to hold the armature 13 in its attracted position.

Should the pinion 33 collide with the end faces of the teeth of theflywheel gear 48 before going into mesh, motion of the armature 13 willnot cease due to the fact there is yielding connection aiorded by thespring 85 between the sleeve 58 and the pinion and clutch assembly.After the pinion 39 engages the end faces of the teeth of the flywheelgear 48, the armature 13 will continue to move toward the left and thesleeve 58 toward the right. While the spring 65 is being compressedbeyond its initial stage of compression, the switch contact is beingengaged with the contacts 83 and 85. When this engagement occurs, themotor will be connected with the battery and will cause the pinion teethto be brought into mesh registration with the spaces between the teethof the engine gear 48. At the instant meshing registration occurs, thespring 65 will be released quickly to move or jump the pinion 39 intomesh with the engine gear 48.

Should the pinion 39 fail to come out of mesh with the engine gear 48after the engine starts, the spring 92 is still free to move the contact84 away from the contacts 83 and 85 due to the fact that the slots |84in links |83 provide thelostmotion connection between the lever 54 andthe armature 13.

The means for preventing the meshing of the motor pinion with the enginegear after the engine becomes self-operative and the pinion has beendemeshed therefrom, will now be described with particular reference toFigures 1, 4, 5, and 6. This means comprises a tubular cup-shaped part|20 having a tubular sleeve |2I/journaled on the part 62 of the sleeve59 of the pinion meshing means, and having an annular flange |22 adaptedto engage the left end face of the flywheel |23 which carries the gear40. The part 62 carries diametrically opposed screw pins |24, each ofwhich is received by a somewhat T-shaped slot |25 provided in thetubular sleeve 2| of the tubular part |29. The head of this T-shapedslot |25 is a somewhat triangular opening dened by wall portions |25which are oblique or inclined to the axis of the pinion. The stem orelongated por tion of the slot is indicated by numeral |21, and is of alength such that the pinion may be meshed with the engine gear whilepart |20 is pressed against an end face of the engine gear, providedthat the pin i2@ remains in alignment with the elongated slot portion|21. Where the stem or elongated portion |21 joins the head portiondefined by oblique wall portions |29, the metal of sleeve |2| providesstop shoulders |28 each of which is adapted to receive pin |24 dependingon which direction the sleeve |20 is rotated with respect to the sleeve`59.

Normally each pin |24 rests in the apex of the head portion of the slot|25 and between the oblique wall portions |26, and is caused to be movedinto that position by spring |30 located between a shoulder |3| of thesleeve 59 and a washer |32 surrounding the sleeve 59 and bearing againstthe left end of the sleeve 2 Therefore, while the engine is at rest, thepinion 39 may be meshed with the engine gear 40 without hindrance by thecup-shaped member |20 since, during this meshing movement, the pin |24will move into the stem portion |21 of the slot 25 and finally into theposition shown in Figure 5, when the pinion 39 is fully meshed with theengine gear 40. During the cranking of the engine the flange |22 of thecup-shaped member |20 will bear against the left face of the engineflywheel |23, but such engagement will be practically noiseless.

If the operator attempts to mesh the motor pinion 39 with the enginegear 40 while the engine is running the tubular, cup-shaped part |28will be rotated due to the frictional engagement of the end face of theywheel |23 and flange |22 of the part |20 thereby causing the slots |25in the sleeve 2| to be shifted relative to the pins |24 carried by thesleeve y5|), one way or the other depending on the direction of therotation of the cup-shaped member |29. Figure 6 shows the conditionwhich will obtain if, looking in the direction of the arrow 'la inFigure 6, the rotation of the ywheel |23 is counterclockwise. Quiteobviously, the rotation of the tubular, cupshaped part |29 will beclockwise. Therefore, the slot |25 nearest the observer of the viewshown in Figure 4 will move upwardly into the position shown in Figure6, and the lowermost portion of the two shoulders |28 provided by themetal of the sleeve |2| adjacent the slot |25 will provide a stop forthe pin |24. Since the pin |24 can move no further toward the right thanis shown in Figure 6, the shifter sleeve U and the clutch and pinionassembly can be moved no further toward the right. The clutch and pinassembly is arrested in its movement and is limited` to a' positionwherein the pinion 39 is still out of engagement with the left endfacesof the gear teeth of the flywheel gear 40, as shown in Figure 6. Inthis way motion of the pinion into engagement with the engine ilywheelgear is positively arrested when the operator attempts to mesh thesegears While the engine is running. Upon release of the operating lever54 the spring 5E restores it and the other parts of the pinion meshingmeans to normal position shown in Figure l. During this return movement,the end ange |22 of the tubular part |29 leaves the end face of theengine gear 23 and each slot part |21 returns to alignment with each pin|24 due to the camming action between each pin |24 and each inclinedwall surface |26 caused by pressure exerted by the spring |30.

While the embodiment of the present invention as herein disclosed,constitutes a preferred form, it is to be understood that other formsmight be adopted, all coming within the scope of the claims whichfollow.

What is claimed is as follows:

1. Engine starting apparatus comprising, in combination, an electricmotor, a pinion driven by the motor and slidab-le axially into mesh witha gear of the engine to be started, means to move the pinion into meshwith the engine gear, and means responsive to rotation of the enginegear for positively blocking movement of the pinion into mesh with theengine gear whilethe engine is running, said last mentioned meanscomprising a locking sleeve adapted to be rotated by the engine gearinto locking position to prevent movement of the pinion toward theengine gear.

2. Engine starting apparatus comprising, in combination, an electricmotor, a pinion driven by the motor and slidable axially into mesh witha gear of the engine to be started, means to move the pinion into meshwith the engine gear, a part movable against an end face of the enginegear and adapted to be rotated thereby, means for transmitting movementfrom the pinion meshing means to said part to cause the latter to bepressed against an end face of the engine gear before the pinion startsto mesh with the engine gear, and devices for interconnecting the pinionmeshing means and said part, said devices being so constructed andarranged as normally to permit such a relative movement between thepinion and part that the pinion may be meshed with the engine gear whilethe part is pressed against the engine gear and to prevent said relativemovement in case the engine gear is rotating before the pinion is meshedtherewith` 3. Engine starting apparatus comprising, in combination anelectric motor, a pinion driven by the motor and slidable axially intomesh with a gear of the engine to be started, means to move the pinioninto mesh with the engine gear, a tubular part surrounding the pinionand pinion meshing means and movable against an end face of the enginegear to be rotated thereby, means for transmitting motion from thepinion meshing means to said port to cause the latter to be pressedagainst an end face of the engine gear before the pinion starts to meshwith the engine gear, and devices for interconnecting the pinion meshingmeans and said part and provided respectively by said means and part,one of said devices being a laterally extending pin and the other amember having a slot for receiving the pin, said slot having anelongated portion extending longitudinally of the axis of the pinionwhereby normally to permit such a relative movement between the pinionand tubular part that the pinion may be meshed with the engine gearwhile the part is pressed against the engine gear, said slot providing astop shoulder which is moved into alignment with the pin in case thetubular part is rotated by the engine gear face prior to the meshing ofthe pinion With the engine gear.

4. Engine starting apparatus comprising, in combination, an electricmotor, a pinion driven by the motor and slidable axially into mesh witha gear of the engine to be started, means to move the pinion into meshWith the engine gear, a tubular part surrounding the pinion and pinionmeshing means and movable against an end face of the engine gear to berotated thereby, yielding means for transmitting motion from the pinionmeshing means to said part to cause the latter to be pressed against ancnd face of the engine gear before the pinion starts to mesh with theengine gear, and devices for interconnecting the pinion meshing meansand said part and provided 'respectively by said means and part, one ofsaid devices being a laterally extending pin and the other a memberhaving a slot for receiving the pin, said slot having an elongatedportion extending longitudinally of the axis of the pinion wherebynormally to permit such a relative movepin to alignment with theelongated portion of the slot when the pinion meshing means returns tonormal position.

5. Engine starting apparatus comprising, in combination, an electricmotor, a pinion driven by the motor and slidable axially into mesh with`a gear of the engine to be started, means to move the pinion into meshwith the engine gear, tubular part surrounding the pinion and pinionmeshing means and movable axially against an end face of the engine gearto be rotated thereby, a slot provided by the tubular part including anelongated portion extending longitudinally of the axis of the pinion apin extending laterally from the pinion meshing means and into saidslot, a spring for transmitting motions from the pinion meshing means tothe tubular part thereby causing one end wall of the slot of the tubularpart to bear normally against said pin whereby normally to maintain anend of the tubular part closer to the engine gear than the pinion, saidelongated slot portion permitting the pinion to be meshed with theengine gear while the tubular part is pressed against an end face of theengine gear, said slot providing a stop portion which is moved intoalignment with the pin in case the tubular part strikes the engine gearwhile rotating whereby to prevent contact between the pinion and enginegear while the engine is running, and said slot providing a surfaceinclined to the axis of the pinion and located between the stop shoulderand an end of said slot, said inclined slot portion cooperating with thepinion under pressure exerted by said spring to restore the alignmentbetween the pin and the elongated portion of said slot when the pinionmeshing means returns to normal position.

HERBAL A. THORNBURG. JAMES- V. BROWN.

